Petroleum-derived polyols have been widely used in the manufacturing of polyurethane foams. Recently, however, there has been an increased interest in the use of renewable resources in the manufacturing of polymers such as polyurethanes. This has led to research into developing natural oil-based polyols that are suitable as full or as partial replacements for petroleum-derived polyols in polymers such as polyurethanes.
One method of making a polyol from an unsaturated natural oil is to epoxidize the natural oil, followed by ring-opening of at least a portion of the epoxide groups to form pendant secondary hydroxyl groups. Ring-opening may be accomplished, for example, by reacting the epoxidized natural oil with a alcohol (e.g., methanol) in the presence of a catalyst (e.g., HBF4). This synthetic route results primarily in the formation of secondary hydroxyl groups that are pendant from the natural oil. Although pendant secondary hydroxyl groups are useful in forming polyurethanes, it is desirable to provide natural oil-based polyols that have faster reactivity due to the presence of at least some primary hydroxyl groups in the polyol.